A Real Martian Anomaly

Who cares about the Face on Mars? It was just an interesting trick of light and shadow—a pareidolia. Now comes a bona fide Martian mystery: pit craters (also known as skylights). Pit craters are thought to be collapse pits into subsurface void spaces. Cave entrances, in other worlds. ;o)

Most of these features are of a volcanic, rather than impact, origin. Both the Earth and the Moon have similar features, entrances to subsurface caverns and tunnels. What wondrous discoveries await future explorers!